Bone insert augment and offset device

Abstract

A bone insert includes a cap having a convex top surface, an elongated stem, and a barrier between the cap and the stem. The stem of the bone insert is inserted into a hole formed in a host bone until the barrier is pressed against the exposed bone. The bone implant can be placed against a small focus contact point on the cap. Liquid cement can be injected into a space volume between the host bone and a bone implant. The cap can be made of a material and/or have surface features that create a strong bond with the cement when the liquid cement cures. The stem can be made of a material and/or have bone ingrowth surface features that create a strong bond with the bone.

What is claimed is: 
     
       1. A bone insert comprising:
 a cap having interdigitation surfaces; 
 a polymer coating on a portion of the cap; 
 flow paths that extend through an outer surface of the cap and the polymer coating; 
 an elongated stem having bone ongrowth surface features on an outer surface of the elongated stem; and 
 a solid barrier structure that physically separates the cap from the elongated stem, prevents liquids from flowing through the cap to the elongated stem and prevents the liquids from flowing through the solid barrier structure; 
 wherein the cap is coupled to an upper surface of the solid barrier structure and the elongated stem is coupled to a lower surface of the solid barrier structure opposite the upper surface, and the solid barrier structure has a width that is wider than an outer width of the elongated stem. 
 
     
     
       2. The bone insert of  claim 1  wherein the cap is formed from a lattice of cap micro struts. 
     
     
       3. The bone insert of  claim 1  wherein the cap is formed from cap micro struts and at least some of the cap micro struts are covered with the polymer coating of the cap. 
     
     
       4. The bone insert of  claim 1  wherein the cap includes cap micro struts that extend through interior portions of the cap. 
     
     
       5. The bone insert of  claim 1  wherein the stem is formed from a plurality of stem micro struts that extend through interior portions of the stem. 
     
     
       6. The bone insert of  claim 1  wherein a width of the solid barrier structure is less than or equal to a width of the cap. 
     
     
       7. The bone insert of  claim 1  wherein a lower surface of the solid barrier structure adjacent to the elongated stem has bone ongrowth surface features. 
     
     
       8. The bone insert of  claim 1  wherein the elongated stem is a porous metal structure and a longitudinal modulus of elasticity of the porous metal structure is greater than a transverse modulus of elasticity of the porous metal structure. 
     
     
       9. The bone insert of  claim 1  wherein the cap has a plurality of cap micro struts that that extend through interior portions of the cap and are coupled at a plurality of strut junctions. 
     
     
       10. The bone insert of  claim 1  wherein the cap includes a center orifice at a geometric center of the cap that is an inlet for the flow paths for a liquid cement into the cap. 
     
     
       11. A bone insert comprising:
 a cap having interdigitation surfaces; 
 a non-metal cover on a portion of the cap; 
 flow paths that extend from an upper outer surface of the cap and the non-metal cover; 
 an elongated stem having bone ongrowth surface features; and 
 a solid barrier structure that physically separates the cap from the elongated stem and prevents liquids from flowing through the solid barrier structure; 
 wherein the cap is coupled to an upper surface of the solid barrier structure and the elongated stem is coupled to a lower surface of the solid barrier structure opposite the upper surface, and the solid barrier structure has a width that is wider than an outer width of the elongated stem. 
 
     
     
       12. The bone insert of  claim 11  wherein the cap is formed from a lattice of cap micro struts. 
     
     
       13. The bone insert of  claim 11  wherein the stem is formed from a plurality of stem micro struts that extend through interior portions of the stem. 
     
     
       14. The bone insert of  claim 11  wherein the cap includes cap micro struts that extend through interior portions of the cap. 
     
     
       15. The bone insert of  claim 11  wherein an exterior surface of the cap is a convex surface that provides a point of contact offset for a bone implant. 
     
     
       16. The bone insert of  claim 11  wherein the elongated stem is a porous metal structure and a longitudinal modulus of elasticity of the porous metal structure is greater than a transverse modulus of elasticity of the porous metal structure. 
     
     
       17. The bone insert of  claim 11  wherein the cap has a plurality of cap micro struts that that extend through interior portions of the cap and are coupled at a plurality of strut junctions. 
     
     
       18. The bone insert of  claim 11  wherein the cap includes a center orifice at a geometric center of the cap that is a tool coupling feature. 
     
     
       19. The bone insert of  claim 11  wherein the cap includes a center orifice at a geometric center of the cap that is an inlet for the flow paths into the cap for a liquid cement. 
     
     
       20. The bone insert of  claim 11  wherein a lower surface of the solid barrier structure adjacent to the elongated stem has bone ongrowth surface features.